One method of manufacturing fiber reinforced metal matrix composite material is by the pressure infiltration process. In this process, fiber performs are infiltrated under high pressure with molten metal. The high pressure is necessary to compensate for the non wetting conditions existing between the reinforcing materials, frequently ceramics, and the molten metal matrix materials.
Typically, the infiltration is done in batches, in which the perform is infiltrated in a pressurized molten metal bath. For example, a perform is placed in a container, a block of metal is placed over the perform, and the temperature and pressure are raised, thereby melting the metal and causing it to infiltrate the perform.
A difficulty arises with continuous processes in which the perform must travel without interruption into, through, and out of the metal bath, in that the entry and exit openings to the bath have not hitherto been satisfactorily sealed to prevent the pressurized molten metal from blowing out of the bath through the openings. Thus, it has been impossible to produce continuous long pieces such as wires, tapes, sheets, or other structural shapes.
An example of a continuous process is given in European Patent Application No. EP 0 304 167 A2. However, at the exit gate, high friction forces cause fast deterioration of orifices and failure of the perform.